.append()

The .append() method will add an element to the end of an array. It allows for single and multiple element additions.

arrayName.append(element)

arrayName.append(contentsOf: [element1, element2, ...])

The method is called on an array instance, and one or more elements can be added by using the contentsOf: parameter.

var topBabyNames = ["Sophia", "Liam"]

topBabyNames.append("Riley")
print(topBabyNames)

topBabyNames.append(contentsOf: ["Olivia", "Noah"])
print(topBabyNames)

This will output:

["Sophia", "Liam", "Riley"]
["Sophia", "Liam", "Riley", "Olivia", "Noah"]

Note: Big-O of this method is O(1).